The wrong or right bin could mean the difference between a notice in the post and a prize.

Liverpool council staff will continue random bin inspections this year and residents found doing the wrong thing will be notified by mail.

But residents who have disposed of materials correctly will win a prize, such as a worm farm.

The inspection program addresses contaminated bins.

Mayor Ned Mannoun said it assisted in waste education programs.

"It is also an opportunity to acknowledge residents found to be doing the right thing," he said.

"The garden and recycling waste is hand sorted at a waste facility, and wrong materials placed in just one bin can contaminate an entire truckload."

Under the program, residents will receive one of two notices in their mail box after an inspection. One will be a bin inspection notice, outlining incorrect materials observed inside recycling or garden waste bins.

The other will be a thank you notice and a congratulatory sticker for placing correct materials in the bins. The council reminds residents that bin liners, plastic bags and any bags marked as degradable, biodegradable or compostable should not be placed in recycling or garden waste bins.